1. Field of the Invention
The present invention relates generally to release mechanisms. More specifically, the present invention relates to actively commanded release mechanisms.
2. Description of the Related Art
The ability to deploy or release connected parts of a device or machine by a mechanism that is secure under extreme forces, yet will reliably actuate when commanded to do so, is extremely useful in situations where a latch or fastener is needed. Additionally, in many design situations, constraints of small size, mass, and operating power make use of several existing actuators impractical due to their complexity and inability to scale to the required size.
Many existing release mechanisms use moving parts and have the need for lubrication. For example, the SQUIGGLE® Motor developed by New Scale Technologies consists of several piezoelectric ceramic actuators that change shape when electrically excited. These actuators are then attached to a threaded nut with a mating screw threaded inside that nut. Applying power to the actuators creates ultrasonic vibrations causing the nut to vibrate in an orbit. The nut's rotation moves the threaded mating screw in-and-out with a linear motion. For this example, both the micro-parts and lubrication needs of the mechanism lead to the possibility of binding and failure.
Some other existing release mechanisms are Non-Explosive Actuators (NEAs). Three NEA designs commonly used for actuation needs are: the Qwknut® designed by Starsys or NEA Split Spool Actuator by NEA Electronics Inc. used on the Cal Poly P-Pod (Poly Pico-satellite Orbital Dispenser); the FRANGIBOLT® actuator model FC2-16-31SR2; and the TiNi Pinpuller® both produced by TiNi Aerospace. The aforementioned NEAs are proven and reliable, but some may be too large for installation within small devices or could impart actuation shock to the system causing damage. In addition, some NEAs can be complex or draw excessive power leading to an increase in the number of failure modes for the actuator and the system using it.